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Memory Requirements
Memory Requirements
The program portion of 177Bug is approximately 512KB of code, consisting of:
❏Download
❏Debugger
❏Diagnostic packages
and is contained entirely in EPROM. The EPROM sockets on the MVME177 are mapped starting at location $FF800000.
177Bug requires a minimum of 64KB of contiguous read/write memory to operate.
The ENV command controls where this block of memory is located. Regardless of where the onboard RAM is located, the first 64KB is used for 177Bug stack and static variable space and the rest is reserved as user space. Whenever the MVME177 is reset:
❏Target PC is initialized to the address corresponding to the beginning of the user space
❏Target stack pointers are initialized to addresses within the user space
❏Target Interrupt Stack Pointer (ISP) set to the top of the user space
At
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